Study On Response Of Overlying Soil Against Dip-Slip Fault And Seismic Isolation Measure For Embankment

Ours country is one of the earthquake countries of the world. In recent years, people were deeply impressed by the frequent occurrence of earthquakes, and pay more and more attention to it. So far, people focus on the study of the ground vibration for structure. But pay less attention to the soil rupture mechanism and influence on superstructure caused by underlying fault movement. In this paper, numerical simulation is carried out for the free-field and interaction of slab foundation for embankment with Dip-Slip fault by ABAQUS. The main contents of this paper are as follows:(1)Summary of key influence factors for fault movement numerical simulation which should pay attention. The main contents as follows:quasi-static method, mesh size, strain softening and material damping. Through the calculation and comparative analysis, find that calculation results are conservative while not consider the above four kinds of influence factors fully. In order to strive to achieve the accurate simulation results, numerical simulation was considered the above four points comprehensively in this paper.(2)Design two kinds of fault types, seven fault dips, two kinds of soil types and four kinds of soil thickness models for the free-field. Study on the rupture property and ground deformation of overlying soil with fault movement, and make parameter analysis. The calculation results show that, there is a close relationship between the width of the zone which with significant ground surface deformation, the location of fault rupture reach the ground surface, the critical fault displacements and the parameters of fault and soil.(3)Apply the rigid slab as a local foundation which with certain width and thickness of embankment. Carry out nine cases on reverse and normal fault respectively by adjusting the relative position between slab foundation and the location of fault rupture reach the ground surface for no foundation(s/b=0.25,0.50and0.75) and fault dip(45°,60°and75°). In order to get better seismic isolation method of slab foundation, analysis and comparison of overlying soil rupture property, embankment surface deformation characteristics and moment distribution of slab foundation were performed. When the overlying soil and embankment rupture characteristics changed, lower disaster occurrence possibility and damage level may happen.(4)We use the quasi-static method to simulate the fault displacement with the highly non-linear characteristic by ABAQUS/EXPLICIT, which eliminate the impact on the calculation result due to seismic wave propagation and emission which may be triggered by fault displacement. In order to make the simulation result and the actual situation of similar, apply the constitutive model Mohr-Coulomb with strain-softening through a combination of software development interface.